Double-material continuous gradient printing feeding system

Abstract

The invention discloses a double-material continuous gradient printing feeding system which comprises a material mixing impeller, a material pool, a material mixing pipe, a screw feeder and a pneumatic pressurization system. Two feeding ports are formed in the top of the mixing pipe, the number of the material pools and the number of the screw feeders are both two, the bottom ends of the two material pools are fixedly connected to the two feeding ports in the top of the mixing pipe, each material pool is connected with one screw feeder, and each material pool is loaded with one material; the material mixing impeller is fixedly connected to the top end of the material mixing pipe and is used for fully mixing materials entering the material mixing pipe; an air inlet is formed in the top of the side wall of the material mixing pipe, and the pneumatic pressurization system injects high-pressure gas into the material mixing pipe through the air inlet to push materials entering the material mixing pipe to rotate and be mixed along the material mixing impeller; and the bottom end of the mixing pipe is a conical extrusion opening. Free high-precision distribution of two materials in the space according to the design structure can be achieved, gradient printing with the double-material ratio being continuously and controllably changed is achieved, and gradient printing with the variable mixing ratio of various types of materials is highly compatible.

Description

Technical Field

[0001] The invention belongs to the field of extrusion biological 3D printing, and in particular relates to a dual-material continuous gradient printing feeding system. Background Art

[0002] With the gradual maturity of 3D printing technology, a variety of biomedical related printing equipment has emerged in recent years, such as: 3D printing equipment based on the molding principles of melt deposition, extrusion, photocuring, laser sintering, etc., using metals, alloys, ceramics, plastics, hydrogels, etc. as printing inks, and applied to bone implants, dental implants, bone guides, medical teaching instruments, etc. For example, when using inorganic substances as printing inks to construct bionic bone structures, when printing structures with different density requirements such as cortical bone and cancellous bone, the conventional solution is to use multiple nozzles to print multiple groups of inks. On the one hand, it is necessary to switch nozzles back and forth to achieve gradient printing of cross-modulus materials with different particle sizes. On the other hand, when configuring materials, it is necessary to separately screen bone powders of various particle sizes and configure separate inks. Summary of the invention

[0003] In view of the shortcomings of the prior art, the present invention proposes a dual-material continuous gradient printing feeding system to solve the problem of dual-material continuous gradient printing in the existing extrusion biological 3D printing technology, completely abandon the existing multi-nozzle cross-modulus material gradient printing method, and use a simple mixing tube as the feeding body to achieve fast, particle size controllable gradient distribution printing.

[0004] The purpose of the present invention is achieved through the following technical solutions:

[0005] A dual-material continuous gradient printing feeding system, comprising a mixing impeller, a material tank, a mixing pipe, a screw feeder and a pneumatic pressurizing system;

[0006] Two feed ports are provided at the top of the mixing tube, and there are two material tanks and two screw feeders. The bottom ends of the two material tanks are fixedly connected to the two feed ports at the top of the mixing tube, and each material tank is connected to one screw feeder, and each material tank is loaded with one material;

[0007] The mixing impeller is fixedly connected to the top of the mixing tube, and is used to fully mix the materials entering the mixing tube;

[0008] An air inlet is provided at the top of the side wall of the mixing tube, and the pneumatic pressurization system injects high-pressure gas into the mixing tube through the air inlet to push the materials entering the mixing tube to rotate and mix along the mixing impeller;

[0009] The bottom end of the mixing tube is a tapered extrusion port.

[0010] Furthermore, a one-way valve is installed at the bottom end of the material pool, so that the material flows from the material pool into the mixing pipe in a one-way manner.

[0011] Furthermore, a plurality of discontinuous spiral blades are installed on the mixing impeller.

[0012] Furthermore, the dual-material continuous gradient printing feeding system is used to be mounted on an extrusion printer frame.

[0013] Furthermore, the extrusion printer frame includes a frame and a three-axis motion mechanism.

[0014] The beneficial effects of the present invention are as follows:

[0015] The dual-material continuous gradient printing feeding system of the present invention can realize the free and high-precision distribution of two materials in space according to the design structure, realize gradient printing with continuous and controllable changes in the dual-material ratio, and is highly compatible with gradient printing with changeable mixing ratios of various types of materials, including but not limited to mutually immiscible materials such as bone meal + hydrogel and mutually fusible materials such as gelatin + sodium alginate, and can achieve high-efficiency and real-time switching of dual-material ratio printing effects. Compared with conventional extrusion printing, the present invention is suitable for integrated printing and molding of dual materials with the same nozzle, greatly improving the efficiency of dual-material extrusion printing, and the entire printing process has a short working cycle, high efficiency and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of a dual-material continuous gradient printing feeding system according to an embodiment of the present invention.

[0017] In the figure, 1 is a mixing impeller, 2 is a material tank, 3 is a mixing pipe, 4 is a screw feeder, and 5 is a pneumatic pressurization system. DETAILED DESCRIPTION

[0018] The present invention will be described in detail below based on the accompanying drawings and preferred embodiments, and the purpose and effects of the present invention will become more clear. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0019] like Figure 1 As shown, the dual-material continuous gradient printing feeding system of this embodiment includes a mixing impeller 1, a material pool 2, a mixing pipe 3, a screw feeder 4 and a pneumatic pressurizing system 5.

[0020] There are two material pools 2 and two screw feeders 4, and two feed ports are provided at the top of the mixing tube 3, which are connected to two material pools 2 respectively, and each of the two material pools 2 is loaded with a material. Each material pool 2 is connected to a screw feeder 4, and the push rod of the screw feeder 4 pushes the material in the material pool 2 into the mixing tube 3. An air inlet is provided at the top of the side wall of the mixing tube 3, and the mixing tube 3 is connected to the pneumatic pressurization system 5 through the air inlet. The mixing impeller 1 is fixedly connected to the top of the mixing tube 3, and a plurality of discontinuous spiral blades are installed on the mixing impeller 1 to fully mix the materials entering the mixing tube 3. The bottom end of the mixing tube 3 is a tapered extrusion port.

[0021] The pneumatic pressurizing system 5 inputs high-pressure gas into the mixing tube 3 as a mixing power for the two materials, pushing the two materials to mix while rotating along the spiral blades, and finally pushing the two materials out of the conical outlet of the mixing tube 3 into a filament.

[0022] The pneumatic pressurizing system 5 can be any device that provides high-pressure gas, such as a compression blower.

[0023] One-way valves are installed at the bottom ends of the two material tanks 2, so that the material flows from the material tanks 2 into the mixing pipe 3 in one direction without backflow.

[0024] When there is a large-particle non-fluid material such as bone meal that is insoluble in another material, one material pool 2 is loaded with the highest proportion of the non-fluid material and fluid material mixture, and the other material pool 2 is loaded with the highest proportion of a single fluid material, thereby ensuring that the non-fluid material can be pushed out of the material pool 2 into the mixing pipe 3 through the screw feeder 4.

[0025] The working principle of the dual-material continuous gradient printing feeding system of this embodiment is as follows:

[0026] After the screw feeder 4 pushes the two materials in the material pool 2 into the mixing tube 3, the air is introduced through the pneumatic extrusion system 5 to push the materials from the top of the mixing tube 3 to the bottom of the mixing tube 3. During this pushing process, the materials are rolled, stirred and mixed evenly by the mixing impeller 1 and become filaments at the conical outlet at the bottom. During the printing process, by controlling the progress of the two screw feeders 4, the mixing ratio of the two materials is switched in real time, thereby realizing the controllable distribution of the gradient of the two material ratio of the molding structure.

[0027] The dual-material continuous gradient printing feeding system of this embodiment is mounted on an extrusion printer frame. The extrusion printer frame is mainly composed of a frame and a conventional three-axis motion mechanism, including but not limited to a Cartesian coordinate system motion mechanism. It can be stably placed on the ground or platform surface by fixing the feet. The entire feeding system is installed on the three-axis motion mechanism and realizes three-axis motion along with the extrusion printer motion mechanism.

[0028] Those skilled in the art can understand that the above are only preferred examples of the invention and are not intended to limit the invention. Although the invention is described in detail with reference to the above examples, those skilled in the art can still modify the technical solutions recorded in the above examples or replace some of the technical features therein with equivalents. Any modification, equivalent replacement, etc. made within the spirit and principle of the invention shall be included in the protection scope of the invention.

Claims

1. A dual-material continuous gradient printing feeding system, characterized in that: It comprises a mixing impeller (1), a material tank (2), a mixing pipe (3), a screw feeder (4) and a pneumatic pressurizing system (5); Two feed ports are provided at the top of the mixing tube (3), and there are two material pools (2) and two screw feeders (4). The bottom ends of the two material pools (2) are fixedly connected to the two feed ports at the top of the mixing tube (3), and each material pool (2) is connected to one screw feeder (4). Each material pool (2) is loaded with one material. The mixing impeller (1) is fixedly connected to the top end of the mixing tube (3) and is used to fully mix the materials entering the mixing tube (3); An air inlet is provided at the top of the side wall of the mixing tube (3), and the pneumatic pressurizing system (5) injects high-pressure gas into the mixing tube (3) through the air inlet, thereby pushing the materials entering the mixing tube (3) to rotate and mix along the mixing impeller (1); The bottom end of the mixing tube (3) is a tapered extrusion port.

2. The dual-material continuous gradient printing and feeding system according to claim 1, characterized in that: A one-way valve is installed at the bottom end of the material pool (2), so that the material flows from the material pool (2) into the mixing pipe (3) in a one-way manner.

3. The dual-material continuous gradient printing and feeding system according to claim 1, characterized in that: The mixing impeller (1) is provided with a plurality of discontinuous spiral blades.

4. The dual-material continuous gradient printing and feeding system according to claim 1, characterized in that: The dual-material continuous gradient printing and feeding system is used to be mounted on an extrusion printer frame.

5. The dual-material continuous gradient printing and feeding system according to claim 4, characterized in that: The extrusion printer frame comprises a frame and a three-axis motion mechanism.

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